Cetuximab-induced skin exanthema: Improvement by a reactive skin therapy.

More than 80% of patients treated with cetuximab develop an acneiform follicular skin exanthema. Grade 3 exanthema develops in 9-19% of these cases, bearing the risk of cetuximab dose-reduction or cessation. We retrospectively analysed a cohort of 20 patients treated with cetuximab and an in-house reactive skin protocol upon development of an exanthema. The reactive skin protocol was built up as follows: grade 1 exanthema: topical cleansing syndet (Dermowas®) + topical metronidazole cream (Rosiced®); grade 2 exanthema: grade 1 treatment + oral minocycline 50 mg twice per day; grade 3 exanthema: grade 2 treatment + topical corticoid (Dermatop®) + topical nadifloxacin (Nadixa®). As soon as a grade 3 had improved to a grade less than or equal to 2, the application of the topical corticoid was ceased. During the initial 12 weeks of therapy with cetuximab, all patients developed a skin exanthema (20/20; 100%). Of these, 2 patients (10%) developed a grade 3 exanthema, 10 patients (50%) experienced a grade 2 and 8 patients (40%) a grade 1 exanthema. Time to onset ranged from 1 to 4 weeks, with the average time to onset being 2.8 weeks. Applying the reactive skin protocol after the first occurrence of an exanthema, the grade of exanthema was downgraded as follows: no patients (0%) had a persisting grade 3 exanthema, while only 2 patients (10%) experienced a persisting grade 2 exanthema and 8 patients (40%) a persisting grade 1 exanthema. In the majority of cases (10 patients; 50%), the reactive skin protocol completely controlled the exanthema (grade 0). The average time to exanthema reduction by one grade was 9.5 days. No dose reductions of cetuximab were necessary. Cetuximab-induced skin exanthema is effectively managed by applying our reactive protocol. The simple protocol is based on a topical cleansing syndet and topical metronidazole and is to be intensified by the addition of oral minocycline, a topical corticoid and topical nadifloxacine, in cases of high-grade exanthema. More comprehensive results are expected from a prospective study with higher patient numbers that is currently being planned.